A new season opal hunting begins! The Rookies face potential disaster from the get go; for Col's Crew, their mining quest is derailed by a serious illness, and the Opal Queen brings in new muscle and new machines for an underground opal hunt.

Rookie Justin has cracks in his equipment and his relationships. Col's Crew are a man down and on their last drum of fuel. The Fire Crew are on a wild goose chase hunting a bounty of fabled fire opal.

For the rookies, there's tension as a new partner leads them on a wild-goose chase underground. Plus, the Cooke brothers' season is off to a bad and dangerous start.

Rookie Justin gambles thousands of dollars on buying his way out of trouble. Opal queen Kelly needs a big find underground or risks going broke. Aaron and Greg's Dragonfly claim might finally pay off.

The Rookies battle their biggest claim yet, and each other; Col's Crew must bring out the old machines to hunt a new opal seam; and it's heating up as the Fire Crew race a fuel leak, chasing legendary red fire opal.

It's last chance for The Rookies' partnership. Col's crew are on a crash course as his reoccurring illness slows them down. The Cooke Brothers fight busted hoses and breakdowns in the quest to strike it rich.

Justin ropes in a stranger in a mad dash to get his excavator across a busy highway. Opal Queen Kelly battles a new claim with a new partner. With Col struck down with illness, Aaron and Greg must push on without him.

Justin recruits fiancee Becky to save him from financial ruin. The Fire Crew face deadly reptiles and a snapped suspension in search of blue fire opal. The Cooke Brothers go 21 metres under.

The Rookies battle busted hoses and finally hit treasure, while Boulder Boys Aaron and Greg bring in an old monster about to self-destruct. At their wash plant, The Cooke Brothers race to beat the worst drought in a decade.

The Rookies, Justin and Becky, risk their lives underground, desperate for a find. Meanwhile opal-hunting legend Col Duff is back, hunting long-forgotten treasure.

The Fire Crew's season rests on a knife-edge as they battle their way back from a disastrous setback. The Opal Queen battles rock-hard walls alone, desperate to find opal.

Rookie Justin tackles a deal that could make or break him. The Boulder Boys race to save their claim from a monsoon flood, while the Cooke Brothers finally hit pay dirt.

It's the end of the mining season and the last chance for the teams. The Rookies gamble their hopes on one last haul of opal, and the Opal Queen makes a final desperate dig.